The Yarlung Zangbo Grand Canyon in Tibet is the deepest and largest canyon in the world – as deep as a 2,000-story building at its lowest point. The Yarlung Zangpo River starts from Mount Kailash before reaching the juncture of Mainling and Medog counties, where it swerves around towering Namjagbarwa, the highest peak in the eastern section of the Himalayas, carving a U-shaped gorge.